<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8" />
    <title>04.箭头函数</title>
</head>

<body>
 
</body>
<script type="text/javascript">
   const fun =function(a){
    return 'hello'
   }
   const fun2 =(b)=>b
   fun2(5)
   console.log(fun2(5))
</script>

</html>